The purpose of the invention is essentially to provide shielding continuously for an electrical cluster connecting, in a particular solution of association of these two elements, the light element and the complementary module; this association solution has advantages, in particular in terms of ease of assembly of the light element with the complementary module, and additionally in terms of size of the complementary module when it is assembled with the light element, or in terms of simplicity of the moulds used in producing the light element. Shielding of an electrical cluster means protection disposed on an electrical cluster which limits the electromagnetic radiation from this cluster so as to satisfy the various standards in force, in particular the EMC (standing for Electromagnetic Compatibility) standard.
The field of the invention is, in general terms, that of motor vehicle lights. In this field, various types of light are known, amongst which there are essentially:                side lights, with low intensity and range;        dipped headlights, with a greater intensity and a range on the road of around 70 metres, which are used essentially at night and where the distribution of the light beam is such that it does not dazzle the driver of a vehicle being passed;        long-range headlights, and additional lights of the long-range type, where the vision area on the road is around 200 metres, and which must be switched off when passing another vehicle so as not to dazzle its driver;        improved headlights, referred to as dual mode, which combine the functions of dipped lights and headlight by incorporating a removable shield;        fog lights.        
The device according to the invention may relate to any one of these lights. Moreover, the complementary module participating in the device according to the invention may comprise a set of electrical and/or electronic and/or mechanical elements intended directly for the functioning of the light or for the functioning of accessory and complex functions associated with the light. More particularly, the complementary module may, for example:                either contain an electronic card of the LCS (Light Control System in English, standing for lighting control system) card type, which serves for managing the implementation of so-called complex functions (FBL, DBL, DRL, Cordy etc) for the light with which this electronic card is associated;        or comprise a control card for controlling a mechanical element of the actuator type;        or be a ballast; a ballast is a special complementary module intended preferably to be integrated in a light device of the dipped headlight type using a discharge lamp as a light source. Ballasts of the Xenon system type are in particular found, frequently referred to as HID (High Intensity Discharge in English, standing for high intensity discharge), which are necessary for creating and maintaining an electric arc used in xenon lamps. An electronic module creates a high voltage within the ballast in order to obtain the electric arc at the light source used. In this type of light, a complementary module of the ballast type is therefore essential for supplying the energy necessary for the correct functioning of the light. The invention will more particularly be described, by way of example solely, in the context of a light device of the dipped headlight type with a complementary module of the ballast type.        
In the state of the art, light devices are known which propose a solution of connection between a light element and a complementary module. Such a light device is illustrated schematically in FIG. 1.
In this figure, a light device 100 is essentially composed of a light element 101 and a ballast 102 of the HID type. In the light element 101, there is in particular a reflector 106 in which a light source 103 has been placed, of the discharge lamp type. The light source 103 produces a light beam which emerges from the light element 101 at an exit surface 108, which constitutes the front part of the light element 101. The light source 103, which rests on a lamp holder element 104, is connected to a high voltage module 105 serving to supply it.
The high voltage module is supplied by means of a first electrical connection 107, constituting an output cluster, which is shielded and which emerges from the light element 101 at the first opening, provided in a bottom face 109 of the light element 101, in which a first connector counter-part 110 has been disposed. This first counter-part 110 is intended to receive a first connector 111 of the ballast 102. The latter comprises a second connector 112, associated with a second connector counter-part 113 disposed at a second opening provided in the bottom face 109 of the light element 101. A second non-shielded electrical connector 117, constituting an input cluster, is connected to the second connector 112; it routes various electrical signals, in particular a supply signal for the ballast and various control signals coming from the vehicle.
The connection between the ballast 102 and the light element 101 is made between the bottom face 109 of the light element 101 and a top face 115 of the ballast 102, at a recess 114 provided in at least part of the bottom face and the rear face of the light element 101, that is to say approximately under the assembly consisting of the reflector 106, the lamp holder element 104 and the high voltage module 105. The ballast 102 is fixed to the light element 101 by means of at least two screws 116 which are disposed vertically in openings provided for this purpose.
In choosing the arrangement of the ballast 102, the least hot region of the light device is in particular considered. Generally this region corresponds to the region situated under the reflector element 101, which moreover is fairly accessible and consequently facilitates assembly: it is at this point that the heat produced by the light source 103 is the least great, and the bottom part of the light element 101 is easier to access than, for example, the rear part.
However, in achieving optimum integration of a complementary module within the light device, a set of constraints must be complied with:                it must be done by means of an assembly operation which is as simple as possible;        it must be compact;        in order to prevent any damage to the elements contained in the ballast, it must take account of the high temperatures which may arise in the functioning of the light device;        it must take account of the need for transmissions of electrical signals between the various components of the light device;        the association between the light device and the complementary module must not give rise to problems of impermeability for any one of these parts.        
However, the assembly between the light element and the complementary module as depicted in FIG. 1 does not comply with these constraints.
First of all, the fact that the connector counter-parts 110 and 113 are disposed vertically on the rear face 109 of the light element 101 poses a first problem: this is because the mould which is used to fabricate the light element 101 opens out in a horizontal direction, and the need to be able to dispose vertical connector counter-parts requires the presence of slides in the mould used. The presence of two connectors is also a problem per se; this is because, the higher the number of connectors, the more tricky and lengthy the performance of the assembly. A first problem is that the light devices depicted are relatively bulky, the complementary module 102 having a considerable height. A fourth problem lies in the complexity of the assembly operation, in particular because of the fixing means used: in the state of the art described, it is necessary to use at least two screws to connect the light element 101 and the ballast 102. The more limited the number of screws, the better is the duration and simplicity of assembly.
To respond to the problems which have just been disclosed, a solution of association between a light element associated with a complementary module, one example embodiment of which is depicted in FIG. 2, has recently been proposed. This solution has in particular the particularity of presenting a single connector for providing the various connections between the various electrical connections participating. FIG. 2 shows a device 200 in vertical section, which is composed in particular of a light element 201 and a complementary module 202 of the HID ballast type, which can in particular comprise an electronic control card 216. Like in FIG. 1, there is found, in the light element 201, in particular a reflector 212 in which a light source 203 has been placed, of the discharge lamp type. The light source 203 produces a light beam which emerges from the light element 201 at an exit surface 208, which constitutes the front part of the light element 201. The light source 203, which rests on a lamp holder element 204, is connected to a high voltage module 205 serving to supply it.
A recess 206 is for example provided in at least a part of the bottom surface 207 and a part 209 of a rear surface 208 of the light element 201, the light device being considered in a normal operating position on a motor vehicle in defining the orientations of these surfaces, the exit surface of the light beam constituting the front face of the light element.
In the light device 200, it has been sought to limit the bulkiness related to the addition of the complementary module of the ballast type 202. Thus a single connector 210 is disposed, for example by snapping in and with a little clearance, as depicted in FIG. 2, on the rear part 209 of the light element 201 which is situated level with the recess 206. The junction of the connector 210 with a suitable contact area of the complementary module can thus be made in a vertical plane, referred to as the contact plane or junction plane, that is to say by moving the ballast 202 in a horizontal direction towards the light element 201, rather than a vertical direction as was the case in the example described in FIG. 1. The size in the direction of the height, which was previously due to the presence of several connector counter-parts and connectors in a horizontal junction plane, has disappeared. With such a new arrangement, the overall height of a light device comprising a complementary module advantageously decreases. The recess 206 is possibly slightly extended horizontally, that is to say it advances a little more under the reflector 212.
However, a light device like the one depicted in FIG. 2 poses a difficulty in production with regard to the electrical connection. This is because it is necessary to make coexist, at a single connection area, various electrical connections, some of which convey signals liable to interfere, by means of electromagnetic interference, with other signals:                a first connection 213 conveys a first set of supply and control signals from the outside of the light device 200 as far as the ballast 202. This first electrical connection 213 enters the light element 201 at an opening 214 in order to be switched to the connector 210. These signals are low voltage signals, of the level of the vehicle battery; the signals are filtered moreover in order not to be noisy;        a second connection 215 conveys, from the connector 210 to the high voltage module 205, a second set of signals, which are supply signals for the light source 203. These signals are produced by the ballast 202 from the first set of signals which have undergone processing within the ballast.        
The latter signals are said to be medium voltage; they have typically a maximum amplitude of a thousand volts. They have high electromagnetic radiation, which may in particular interfere with the first set of signals and various control signals used by the electronic card 216, the various signals being directly adjacent at least with regard to the connector 210. This is because, even if the connection 215 is shielded, the connector 210 to which it is connected is, in the state of the art, not shielded. It is therefore necessary to find a solution for preventing this interference which arises at the connector 210. One solution proposed in the state of the art is to dispose various filters on the electronic card 216 and/or ferrites in the ballast 202 and/or around the cluster. Such a solution does however pose a problem of cost and complicates the manufacture of the ballast 202.
One object of the present invention is to respond to this problem. In general terms, a shielding device is proposed in the invention, involving in particular connector, to which there are connected firstly a connection conveying signals which interfere weakly in terms of electromagnetic radiation, and secondly a connection conveying signals which radiate sufficiently to interfere with the adjacent signals, said connector providing the shielding, in terms of electromagnetic radiation, of the second connection as far as its contacts disposed in the connector. Though the invention essentially makes reference to an arrangement of the complementary module 202 as depicted in FIG. 2, it is directly applicable to all light devices equipped with a complementary module intended to be associated with a light element and for which the electrical connection between these two elements is made by means of a single connector.
To this end, in the invention, it is proposed essentially to incorporate in the single connector a shielding element intended to surround solely contact areas affording connection with a shielded cluster. In a particular example embodiment of the device according to the invention, the electronic card can be embedded directly in the partially shielded connector, that is to say it has a set of contact areas on its surface which are directly accessible to the various contact areas of the connector when the electronic card is fitted in the connector. In this case, it is not essential to shield the various contact areas of the electronic card.